1. Field of the Invention
The present invention relates to a method for manufacturing ligneous material by means of binding wood pieces, thin wood plates, wood fiber, and the like, using a binder.
2. Description of Related Art
Ligneous materials made by means of binding wood fiber and the like, using a binder, exhibit a superior strength, a low directional stability, and uniform quality, leading to ease in processing, and thus can provide molded products with curved surfaces, in addition to plate-shaped molded products. Hence, they are used as material for building materials, furniture, and the like. A method for manufacturing such ligneous materials is disclosed in, for example, Japanese Patent Number 2500491. The aforementioned publication discloses a molded product manufactured by means of integrating acetylated wood fiber, using a phenol resin adhesive. Additionally, the degree of acetylation of the aforementioned acetylated wood fiber is in the range of 10xcx9c30%.
However, the aforementioned molded product requires an acetylating agent, which is expensive, thus leading to increased costs, and also creates a problem in the release of formaldehyde.
The object of the present invention is to provide a method for manufacturing an inexpensive ligneous material which exhibits only minor dimensional changes from moisture, wherein only a small amount of formaldehyde is released.
The method for manufacturing ligneous material according to the present invention is characterized in comprising the steps of: acetylating wood elements selected from among wood pieces crushed from lumber, thin wood plates peeled from lumber, and wood fiber obtained by means of defibrating lumber, such that the degree of acetylation (weight percent gain) is 7% or greater, and preferably 7xcx9c18%; and binding the resultant acetylated wood elements, using a binder containing polyisocyanate.
Additionally, the method for manufacturing ligneous material according to the present invention is also characterized in comprising the steps of: acetylating a portion of wood elements selected from among wood pieces crushed from lumber, thin wood plates peeled from lumber, and wood fiber obtained by means of defibrating lumber, such that the average degree of acetylation (weight percent gain) is 7% or greater, and preferably 7xcx9c18%; and binding the resultant acetylated wood elements, using a binder containing polyisocyanate.
In addition, in each of the aforementioned methods for manufacturing ligneous material, different types of the aforementioned wood elements may be bound together, using a binder containing polyisocyanate, and laminated in a multi-layer structure comprising two or more layers.